SEMTECH UR7HCTS2-U860

ScreenCoderTM UR7HCTS2-U860
High-Performance USB
Touch Screen Controller / Digitizer
HID & SYSTEM MANAGEMENT PRODUCTS, MOUSECODERTM FAMILY
DESCRIPTION
FEATURES
The ScreenCoder USB IC is the
first single IC that seamlessly
interfaces ANY 4- or 8-wire
resistive touch screen to a USBequipped system. It is also the
first touch screen controller IC on
the market designed to
accommodate a very wide range of
size, capacitance and resistance of
4- or 8-wire touch screens,
providing a universal performance
solution among different OEM
products and touch screen
vendors. This unique feature of the
IC provides OEMs with a wide
variety of interchangeable touch
screen options.
TM
Unlike digitizers, the
ScreenCoderTM USB integrates a
digitizer with a controller that
performs all touch detection, noise
filtering, error elimination and
provides the host with processed
and stable positioning data over
USB. Semtech’s unique motion
algorithms provide high resistance
to RF and other noise sources
resulting in precise, non-jittery
cursor control.
• Controller & digitizer in a single IC
• Interfaces the system via USB
• Works with ANY 4- or 8-wire
resistive touch screen regardless
of size, material or vendor
• Provides high resolution - 1000
points per axis, enabling IC to
make precise drawing and
signature captures
• Accurate, quick touch response
due to Semtech’s advanced
sampling technology and
algorithms
• Highly resistant to RF and other
noise
• No digitizer or external A/D
necessary
• Fully compliant with USB HID
specifications; works with native
USB drivers including Windows®
98, Me and 2000
• Convienent calibration applet
offered free of charge
• Uses slim 36-pin, SSOP package
• Customized versions available
APPLICATIONS
• Handhelds/Notebooks
• Portable Devices
• Interactive Kiosks
• Industrial/Custom Touch Screens
PIN ASSIGNMENTS
1
RSVD1
RSVD2
RSVD3
SXL
SYT
SYB
SXR
RSVD4
RSVD5
RSVD6
RSVD7
VREF
_RESET
VSS2
VDD
OSCIN
_OSCOUT
VSS
Ideal application for the
ScreenCoderTM USB include
portable devices, interactive kiosks
and industrial / custom displays
with integrated touch screens.
The universal features of the
ScreenCoderTM USB, as
implemented in both the system
and the sensor interface, reduce
the development effort and cost of
touch input based systems. The
ScreenCoderTM USB is available in
a slim, 36-pin SSOP package.
36
36-pin SSOP
18
19
ScreenCoder, MouseCoder are trademarks of
Semtech Corp. All other trademarks belong to
their respective companies.
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
1
www.semtech.com
D+
D_RB
RSVD13
XR2
YB2
YT2
XL2
RSVD12
RSVD11
USBV
RSVD10
RSVD9
RSVD8
XL1
YT1
YB1
XR1
ORDERING CODE
Package Options
36-pin, Plastic SSOP
Pitch in mm’s
0.8mm
TA=-20° C to +85° C
UR7HCTS2-U860-DR
Other Materials
ScreenCoderTM USB Eval Kit
Type
Evaluation Kit
Order number
EVK7-TS2-U860-XXX
BLOCK DIAGRAM FOR THE UR7HCTS2-U860
Right Button
Power
Management
Section
Switch Interface
Power -On Reset
Drivers for Touch
Screen
Touch Panel
Interface
4
Sense Lines
4
16-Bit Timer
Sensor Interface
Oscillator Circuit
USB
Communication
Interface
OSCIN
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
D+
D-
_OSCOUT
2
www.semtech.com
FUNCTIONAL DESCRIPTION
The UR7HCTS2-U860 consists
functionally of five major sections
(see the Functional Diagram on
Page 2). These are the Sensor
Interface, the Power Management
Section, the 16-Bit Timer, the
Oscillator Circuit and the USB
Interface.
OSCILLATOR
This IC has a built-in Oscillator
circuit capable of operations with
an external 6.00 MHz Clock source,
or a Ceramic Resonator (preferably
with built-in Load Capacitors) or a
Crystal with external Load
Capacitors.
POWER MANAGEMENT
According to the USB specification,
if there is no activity of the USB port
for 3 ms, the system is considered
to be in a suspended state. The
ScreenCoderTM USB IC, on
detecting that the system is in
suspend, will check the state of the
touch screen and the right button.
If there is no touch pressure
detected or no button pressed, the
ScreenCoderTM USB enters into the
suspended state. In suspend the
IC fully complies with the USB
specification for the power
consumption, dissipating current
only in the USB-mandated pull-up
for the device identification.
PIN DEFINITIONS
Mnemonic Pin #
Power:
VDD
15
VSS
14,18
3.3V
22
_Reset
13
Oscillators:
OSCI
16
OSCO
17
USB:
D35
D+
36
Touch
Screen:
XR1, XR2
19,32
YB1, YB2
31,20
YT1, YT2
21,30
XL1, XL2
22,29
SXR
7
SYB
6
SYT
5
SXL
4
VREF
12
SOUT
23
_RB
34
RDVD1-13
1-3,8-11
23-25,
27-28
33
Type
Name and Function
P
P
P
Power Supply
Ground
USB Reference Voltage Out
I
Reset
I
O
Oscillator Input
Oscillator Output
I/O
I/O
USB D- Line
USB D+ Line
I/O
I/O
I/O
I/O
Al
Al
Al
Al
Al
O
I
I/O
Touch Screen Right Drive Pins
Touch Screen Bottom Drive Pins
Touch Screen Top Drive Pins
Touch Screen Left Drive Pins
Touch Screen Sense Pin: for X Right
Touch Screen Sense Pin: for Y Bottom
Touch Screen Sense Pin: for Y Top
Touch Screen Sense Pin: for X Left
Voltage Reference for A/D Converter
Output control data to A/D Converter
Mouse Right Button
Reserved for future use
Note: An underscore before a pin mnemonic denotes an active low signal.
Pin Types Legend: I=Input; O=Output; I/O=Input or Output; P=Power; Al= Analog Input
POWER MANAGEMENT (CON’T)
If the system does not allow remote wake-up, the ScreenCoderTM USB will
not send resume messages to the system when it is awoken by activity on
the touch screen or button.
Another technique the IC uses to
conserve power is called remote
wake-up. If the system relies on the
device to perform wake-up, the IC
will send a resume message to the
system when there is activity on the
touch screen or button.
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
3
www.semtech.com
TOUCH SCREEN SENSOR INTERFACE
The ScreenCoderTM USB can acquire data from any 4- or 8-wire resistive touch screen sensors. The sensor
interface has the following features:
Touch detection
The IC periodically checks touch pressure applied to the panel. If there is no touch, the IC will not perform
measurements and will not send data to system. When touch pressure is detected, the IC further qualifies and
determines the amount of pressure. Semtech’s proprietary, patent-pending touch detection algorithm performs this
test very quickly, accommodating sensors with various plate-to-plate capacitances.
Touch Measurement
Position information is only collected if it has been determined that the touch pressure is sufficient for an accurate
reading. To obtain position information from the Resistive Touch Screen Sensor, the ScreenCoderTM USB uses four
internal drivers (two pins for each driver) and four sense lines. During sampling, the drivers of the X-axis are
activated by setting one X-drive high and the other X-drive low. The drivers for Y-axis are set floating. This action
produces a voltage gradient across the touch screen's surface in the X direction. The internal A/D measures both
the voltage across the activated X-plane and the voltage potential between the planes. Next, the drivers for the Yaxis are activated while the drivers for X-axis are set floating. Again, the internal A/D measures both voltage across
the activated plane and potential between the planes. The X and Y absolute position is obtained from these four
A/D measurements. The IC keeps measuring the touch pressure even while the positioning data is acquired. If
insufficient touch pressure is detected during sampling of the position, the current data set will be rejected.
Touch algorithm
Due to vibration and electrical noise, the raw data can not be used directly. Internal data processing delivers
consistent position accuracy and quick touch response.
Resolution
The ScreenCoderTM USB uses a built-in A/D converter to get the touch position. The maximum touch screen
resolution is 1000 points per direction. Resolution varies somewhat for different touch screen sensors, due to
voltage droop on connecting wires.
Touch screen from different makers
Operating parameters for the touch screens from different manufacturers vary depending on the size of the sensor,
material it is made from, and mechanical construction. The ScreenCoderTM USB takes these properties into
account, and adjusts automatically for plate-to-plate capacitance, intrinsic plate resistances, etc.
Buttons
The ScreenCoderTM USB implements both left and right buttons, however, there is no physical left button. Left
button press is reported when there is touch pressure on the panel. The left button is released when there is no
pressure on the panel. The right button is a physical button, and can be used individually.
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
4
www.semtech.com
USB FUNCTIONALITY
The ScreenCoderTM USB is a lowspeed USB device with remote
wake-up capability. The IC asks
the system to send report requests
every 10ms according to USB
specification for low speed device.
The ScreenCoderTM USB describes
itself as a pointer, and provides
absolute position data to the
system.
USB DESCRIPTORS
Offset
Part
Device Descriptor
0
bLength
Value
Description
1
0x12
Numeric expression specifying the size of
device descriptor
Device descriptor type
USB HID spec release number 01.00
Class code
Sub class code
Protocol code
Maximum packet size for EP0
USAR's vendor ID
USAR ScreenCoderTM USB Product ID
Device release number
Index of string descriptor describing
manufacturer
Index of string descriptor describing
product
Index of String descriptor describing
serial number
Number of possible configurations
1
bDescriptonType
1
2
bcdUSB
2
3
4
5
6
8
10
12
14
bDeviceClass
bDeviceSubClass
bDeviceProtocol
bMaxPacketSize0
idVendor
idProduct
bcdDevice
iManufacture
1
1
1
1
2
2
2
1
0x01
0x0100
0x00
0x00
0x00
0x08
0x047A
0x0004
0x0061
0x04
15
iProduct
1
0x0E
16
iSerialNumber
1
0x00
17
bNum-
1
0x01
Configuration Descriptor
0
bLength
1
1
bDescriptorType
1
2
wTotalLength
2
4
bNumInterface
1
0x09
0x02
0x0022
0x01
5
6
7
bConfigurationValue1
iConfiguration
1
bmAttribute
1
0x01
0x00
0xA0
8
MaxPower
1
0x32
Interface Descriptor
0
bLength
1
1
bDescriptorType
1
2
bInterfaceNumber 1
3
bAlternateSetting 1
4
bNumEndpoints
1
5
bInterfaceClass
1
6
bInterfaceSubClass 1
0x09
0x04
0x00
0x00
0x01
0x03
0x00
7
8
0x02
0x00
bInterfaceProtocol 1
iInterface
1
HID Descriptor
0
bLength
1
bDescriptorType
2
bcdHID
4
bCountryCode
5
bNumDescriptor
6
bDescriptorType
7
wDescriptorLength
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
Size
5
1
1
2
1
1
1
2
0x09
0x21
0x0100
0x00
0x01
0x22
0x0038
Size of configuration descriptor in bytes
Configuration (assigned by USB)
Total length of data returned for this
Number of interfaces supported by this
configuration
Current configuration value
Configuration string descriptor index
Configuration characteristics - bus
powered, with remote wakeup
Maximum power consumption of USB
device 100 mA
Size of Interface descriptor in bytes
Interface descriptor type
Number of interface
Number of alternate setting
Number of endpoint
Class code (HID)
Subclass code (nor boot interface
subclass)
Protocol code = mouse
Index of string descriptor describing this
interface
Size of HID descriptor in byte
HID descriptor type
HID Spec release number
Hardware target country
Number of HID class descriptor follow
Report descriptor type
Total length of report descriptor
www.semtech.com
USB DESCRIPTORS, (CON’T)
Offset
Size
Value
Description
Endpoint Descriptor
0
bLength
1
bDescriptorType
2
bEndpointAddress
3
bmAttribute
4
WMaxPacketSize
6
BInterval
1
1
1
1
2
1
0x07
0x05
0x81
0x03
0x0005
0x0A
Size of endpoint descriptor in bytes
Endpoint descriptor type
Endpoint address (IN, Endpoint 1)
Endpoint's attribute (interrupt)
Maximum packet size
Interval for polling (poll every 10 ms)
String Descriptor
1
bLength
2
bDescriptorType
3
bString
5
bLength
6
bDescriptorType
7
bString
1
1
2
1
1
8
Length of string description in bytes
Descriptor type = String
LangID code = English
Length of string descriptor
Descriptor Type = String
Manufacturer
15
16
17
bLength
bDescriptorType
bString
1
1
20
0x04
0x03
0x0904
0x0A
0x03
‘U’,0,’S’,
0,’A’,0,
’R’,0
0x3A
0x03
‘S’,0,’c’
0,’r’,0,
’e’,0,etc.
Offset
Data
Report
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
43
45
48
50
52
54
55
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
Part
6
Descriptor
05 01
09 01
A1 01
09 01
A1 00
05 09
19 01
29 03
15 00
25 01
95 03
75 01
81 02
95 01
75 05
81 01
05 01
09 30
09, 31
15, 00
26, FF 7F
35, 00
46, FF 7F
75, 10
95, 02
81, 02
C0
C0
Length of string descriptor
Descriptor type = String
“ScreenCoderTM UR7HCTS2-U860”
Mnemonic
Value
Usage Page
Usage
Collection
Usage
Collection
Usage page
Usage Minimum
Usage Maximum
Logical Minimum
Logical Maximum
Report Count
Report Size
Input
Report Count
Report Size
Input
Usage Page
Usage
Usage
Logical Maximum
Usage Maximum
Physical Minimum
Physical Maximum
Report Size
Report Count
Input
End Collection
End Collection
Generic Desktop
Pointer
Application
Pointer
Physical
Buttons
1
3
0
1
3
1
Variable
1
5
Constant
Generic Desktop
X
Y
0
15 bits 7FFF
0
15 bits 7FFF
16 bits
2
Variable
www.semtech.com
GND
10nF
+/-10% X7R
C6
10nF
+/-10% X7R
C5
10nF
+/-10% X7R
C4
10nF
+/-10% X7R
C3
RN1
4.7K
www.semtech.com
XL
YT
YB
XR
GND
0.1uF
C1
VDD
6.00MHz
Y1
TC54VC4502ECB
11
1
Y1 == 6.00 MHz Ceramic Resonator with
n Load
Built-i
Capacitors.
Crystals can NOT
e used.
b
18
17
16
15
14
13
12
10
9
8
7
6
5
4
3
2
1
U2
GND
U860 == USB Out, 6.00 MHz, 8/4-wire, Model0
Connect Drive and Sense lines together for the 4-wire sensor
NOTES:
SXR
SYB
SYT
SXL
2
1
SENSE_XL
SENSE_YT
SENSE_YB
SENSE_XR
4
3
DRV_XL
DRV_YT
DRV_YB
DRV_XR
6
5
See Not es
8
7
RIGHT BUTTON
2
7
3
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
VSS
OSCOUT
OSCIN
VDD
VSS2
RESET
VREF
RVSD7
RVSD6
RVSD5
RVSD4
SXR
SYB
SYT
SXL
RVSD3
RVSD2
RVSD1
UR7HCTS2-U860
36-pin SSOP
XR1
YB1
YT1
XL1
RVSD8
RVSD9
RVSD10
USBV
RVSD11
RVSD12
XL2
YT2
YB2
XR2
RVSD13
RB
D-
D+
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
GND
30
30
0.1uF
C7
R3
1.5K
(C)2000 USAR, A Semtech Company
ScreenCoder(TM) USB UR7HCTS2-U860
R2
R1
2
3
5
SW1
6
holes
SHIEL D
GND
1
4
Mounting
J1
VDD
10uF
C2
SUGGESTED INTERFACING FOR THE SCREENCODERTM USB UR7HCTS2-U860-DR
F
A
A2
36
19
1
18
E
HE
MECHANICAL INFORMATION FOR DR (36-PIN SSOP) PACKAGE
A1
L1
D
L
e
y
b
c
Recommended Mounting Pad
Symbol
e1
e
b2
I2
A
A1
A2
b
c
D
E
e
HE
L
L1
y
b2
e1
I2
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
8
Dimension in Millimeters
Min
Nom
Max
–
–
2.4
0.05
–
–
–
2.0
–
0.35
0.4
0.5
0.13
0.15
0.2
14.8
15.0
15.2
8.2
8.4
8.6
–
0.8
–
11.63
11.93
12.23
0.3
0.5
0.7
–
1.765
–
–
–
0.15
0°
–
10°
–
0.5
–
–
11.43
–
–
1.27
–
www.semtech.com
ELECTRICAL SPECIFICATIONS
Absolute Maximum Ratings
Ratings
Supply Voltage
Input Voltage
Current Drain per Pin
(not including Vss or Vdd)
Operating Temperature
UR7HCTS2-U860
Storage Temperature Range
Symbol
Vdd
Vin
I
Value
-0.3 to 7.0
Vss -0.3 to Vdd +0.3
20
Unit
V
V
mA
Ta
T low to T high
-20 to +85
-40 to +125
°C
°C
°C
Tstg
DC Electrical Characteristics, Temperature range=T low to T high unless otherwise noted)
Characteristic
Symbol
Min
Typ
Max
Supply Voltage
3.0
5.0
5.5
Output Voltage (10 µA load)
Voh
Vdd–0.1
Vol
0.1
Input High Voltage
Vih
0.8 x Vdd
Vdd
Input Low Voltage
Vil
Vss
0.2xVdd
Input Current
Iin
+/- 10
Supply Current
(Vdd=5.0 Vdc+/-10%, Vss=0)
Idd
3.0
TBD
Unit
V
V
V
V
µA
mA
Control Timing (Vdd=5.0 Vdc +/-10%, Vss=0 Vdc, Temperature range=T low to T high unless otherwise noted)
Characteristic
Symbol
Min
Typ
Max
Unit
Frequency of Operation
fosc
MHz
Crystal Option
6.0
External Clock Option
6.0
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
9
www.semtech.com
SCREENCODERTM USB UR7HCTS2-U860 BILL OF MATERIALS
UR7HCTS2-U860-DR BOM
Description
Quantity
Capacitors:
C1, C7
2
C2
1
C3, C4, C5, C6
4
Connectors:
J1
1
ICs:
U1
1
U2
1
Resistors:
R1, R2
2
R3
1
RN1
1
Resonator:
Y1
1
Button:
SW1
1
Manufacturer
Part#
Description
Generic
Generic
Generic
Any
Any
Any
.1uF Capacitor
10uF Capacitor
0.01uF Capacitor, 10% X7R or better
Generic
Any
USB Connector
USAR
TelCom
UR7HCTS2-860
TC54VC2702ECB
ScreenCoderTM Controller
Low-power Reset Voltage Detector
Generic
Generic
Generic
Any
Any
Any
30 Ohms Resistor
1.5k Resistor
4x, 4.7k Resistor Network
Panasonic
EFO-S6004E5
6.00MHz Ceramic Resonator, w/ built-in Load Caps
Generic
Any
Push Button
Revised 10/03/00
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
10
www.semtech.com
Page Left Blank Intentionally
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
11
www.semtech.com
For sales information
and product literature,
contact:
HID & System Mgmt Division
Semtech Corporation
568 Broadway
New York, NY 10012
[email protected]
http://www.semtech.com
212 226 2042 Telephone
212 226 3215 Telefax
Semtech Western Regional Sales
805-498-2111 Telephone
805-498-3804 Telefax
Semtech Central Regional Sales
972-437-0380 Telephone
972-437-0381 Telefax
Semtech Eastern Regional Sales
203-964-1766 Telephone
203-964-1755 Telefax
Semtech Asia-Pacific Sales Office
+886-2-2748-3380 Telephone
+886-2-2748-3390 Telefax
Semtech Japan Sales Office
+81-45-948-5925 Telephone
+81-45-948-5930 Telefax
Semtech Korea Sales Sales
+82-2-527-4377 Telephone
+82-2-527-4376 Telefax
Northern European Sales Office
+44 (0)2380-769008 Telephone
+44 (0)2380-768612 Telefax
Southern European Sales Office
+33 (0)1 69-28-22-00 Telephone
+33 (0)1 69-28-12-98 Telefax
Central European Sales Office
+49 (0)8161 140 123 Telephone
+49 (0)8161 140 124 Telefax
Copyright 2000-2001 Semtech Corporation. All rights reserved.
MouseCoder, ScreenCoder and Self-Power Management are
trademarks of Semtech Corporation. Semtech is a registered
trademark of Semtech Company. All other trademarks belong to
their respective companies.
INTELLECTUAL PROPERTY DISCLAIMER
This specification is provided "as is" with no warranties whatsoever
including any warranty of merchantability, fitness for any particular
purpose, or any warranty otherwise arising out of any proposal,
specification or sample. A license is hereby granted to reproduce
and distribute this specification for internal use only. No other
license, expressed or implied to any other intellectual property
rights is granted or intended hereby. Authors of this specification
disclaim any liability, including liability for infringement of proprietary
rights, relating to the implementation of information in this
specification. Authors of this specification also do not warrant or
represent that such implementation(s) will not infringe such rights.
Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101
12
www.semtech.com